Ok, I've look at the walkthroughs and they all say the same thing about diamond steppe island.
"Use the Hookshot to climb from tree to tree (for the first tree, stay as close to the lowest step as you can) and enter the Secret Cave at the top step."
How do i use the hookshot from the boat? It only goes into the water to get treasure. I've tried hitting every button i can think of and it won't let me target the tree on the bottom of the island. If there is a way to use the hookshot like in normal battle on the boat I can't figure it out. Please help me. Thanks in advance.